Sofa



FIG. 1 is a front perspective view of a sofa, showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a side view thereof, the opposite side view being a mirrorimage hereof.

I claim the ornamental design for a sofa, as shown and described.